title: Calibration of multiplexed fiber-optic spectroscopy.
abstract: Large-scale commercial bioprocesses that manufacture biopharmaceutical products such as monoclonal antibodies generally involve multiple bioreactors operated in parallel. Spectra recorded during in situ monitoring of multiple bioreactors by multiplexed fiber-optic spectroscopies contain not only spectral information of the chemical constituents but also contributions resulting from differences in the optical properties of the probes. Spectra with variations induced by probe differences cannot be efficiently modeled by the commonly used multivariate linear calibration models or effectively removed by popular empirical preprocessing methods. In this study, for the first time, a calibration model is proposed for the analysis of complex spectral data sets arising from multiplexed probes. In the proposed calibration model, the spectral variations introduced by probe differences are explicitly modeled by introducing a multiplicative parameter for each optical probe, and then their detrimental effects are effectively mitigated through a "dual calibration" strategy. The performance of the proposed multiplex calibration model has been tested on two multiplexed spectral data sets (i.e., MIR data of ternary mixtures and NIR data of bioprocesses). Experimental results suggest that the proposed calibration model can effectively mitigate the detrimental effects of probe differences and hence provide much more accurate predictions than commonly used multivariate linear calibration models (such as PLS) with and without empirical data preprocessing methods such as orthogonal signal correction, standard normal variate, or multiplicative signal correction.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, Hunan, P.R. China. zpchen2002@hotmail.com
authors.forename: Zeng-Ping
authors.initials: ZP
authors.lastname: Chen
authors.forename: Li-Jing
authors.initials: LJ
authors.lastname: Zhong
authors.forename: Alison
authors.initials: A
authors.lastname: Nordon
authors.forename: David
authors.initials: D
authors.lastname: Littlejohn
authors.forename: Megan
authors.initials: M
authors.lastname: Holden
authors.forename: Mariana
authors.initials: M
authors.lastname: Fazenda
authors.forename: Linda
authors.initials: L
authors.lastname: Harvey
authors.forename: Brian
authors.initials: B
authors.lastname: McNeil
authors.forename: Jim
authors.initials: J
authors.lastname: Faulkner
authors.forename: Julian
authors.initials: J
authors.lastname: Morris
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D016466:CHO Cells; D002138:Calibration; D006224:Cricetinae; D003412:Cricetulus; D055100:Optical Fibers; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis / Q000295:instrumentation*
chemical_list: D000911:Antibodies, Monoclonal; D012997:Solvents